20 whp increase????

1st)Boost Designs 4 Piece Underdrive Pulley Set claims to give an additional 20 whp. (1)Is this wishful thinking or does it BUT on a car that already has like 350 whp??(2) What do you estimate the WHP increase to be on a stock setup.

2nd) The Fidanza Aluminum Flywheel offered for the s13 mentions that you rev faster, accelerate faster, and spools the turbo faster.(3) If I plan on doing a N/A setup this will still be a very good upgrade correct? The flywheel is supposed to shorten the crank; thus no matter what setup you have you will still get a HP increase and a much more responsive launch (acceleration),(4) right?

EDIT: (5) Do you have to buy the set that includes the alternator, water or is it just recommended to get all new pulleys at once? Cuz I was also thinking about just buying the Unorthodox pulley.(6) What is the best pulley? I know alot of questions but try and answer them please. Thanx.

Well, i dont know about the pulleys... but to answer your questions about a lightweight flywheel.. yes no matter what setup u have, i think its a good investment... some people say that because of the lesser weight you can rev quicker but it also slows RPM down quicker, which isnt good for drag racing... but i say, shift quicker.

Lighter flywheels do not increase power. They allow the engine to reach speed quicker allowing you to reach the existing horespower quicker. That would explain increases in ET but not in MPH at the racetrack. Good investment? Yes.

Pulleys generally underdrive accessories. It is only a function of leverage. Larger pulley drives accessories faster, but at the loss of more energy taken to drive them. Smaller pulley drives accessories slower, but takes less energy to spin. Very similar to gearing or tires. The gain in power would be proportional to the amount of power you are making. I would e-mail PJ at Boostdesigns. His E mail address is [email protected] They are also merging with ATR if you didn't know.

yea ligheter flywheels dont add horsepower but they do free up horse power

flywheel is deifnitely more worth it than pullies........ they don't do crap.

if i were you i'd save another few hundred bucks and do a turbo upgrade. if you're gonna be spending more than $750 in performance, do yourself justice and get a turbo.

Not free up horsepower. They only allow you to reach the existing HP quicker. The only way to increase HP is to get more air in and out of the engine. Dyno it and see.

It won't increase the horsepower output of the engine, but it will increase the wheel horsepower.

No. Lightened flywheels do not increase engine power what-so-ever. They only increase engine response and the engine's ability to accelerate faster, thus causing it to reach existing HP faster.

THE ONLY WAY TO INCREASE ENGINE POWER IS TO GET MORE AIR IN AND OUT OF THE ENGINE WITH THE PROPER AMOUNT OF FUEL.

Nitrous can be considered concentrated oxygen so that also falls into getting more air into the engine.

Like I said, it doesn't increase the power of the engine, it decreases the loss of power in the drivetrain which in terms increases the wheel horsepower, but the power output of the actual engine is unchanged.

Jeff explains this topic much better than I (http://ka-t.org/ipw-web/bulletin/bb/viewtopic.php?t=2731)

Touché.

Whether its lightened pulleys, crank, rods, pistons, flywheel, drive shaft, wheels, or even the body, it all comes down to the simple fact that you are reducing the amount of mass the engine must accelerate. The difference between all of the aforementioned parts and the body is that the body is only accelerated linearly by the engine. All the others have circular or recipricating acceleration in addition to the linear acceleration.

Here is a simple experiment you can do with your 240SX (or any car with a belt driven cooling fan): First run your car flat out noting the straight line performance. Then remove 4 lbs from the car, lets say the jack and associated tools. Repeat the test and you'll find that you can't feel or even measure the difference. Replace the items and then remove your fan from the from of the water pump, this weighs approx. 4 lbs. Repeat the test and you should be able to feel the difference.

This is because you have reduced the rotating mass more substantially than the same weight reduction to the whole car. i.e. 4 lbs = a higher % of the rotating mass than the % reduction -4 lbs makes to the total vehicle weight. The total rotating mass (accessories, crank, flywheel, clutch, gearshafts, driveshaft, differential gear, axels, wheels, and tires)of the car probably weighs something like 300 lbs. So you've made a 1.33% reduction in rotating mass. Now say your 240SX weighs 3000 lbs. A 4 lb reduction results in only 2/15 of 1% reduction or -0.133%. Get it?

BTW: the fan beating the air results in a 5 hp loss around 5600 rpm but almost no loss below 4000 so the gains you felt below 4000 rpm are purely from the reduction in rotating mass. Now just imagine the gains you'd get by removing another 7 lbs from the pulleys, 10 lbs from the flywheel, and 10 lbs from the driveshaft!

Sure its quicker, but no more HP is picked up.

Do your expirment at the track and see what you trap at before and after. Only thing that will improve is your ETs.

On this we agree. On the strip the fan adds 0.189-0.157 seconds to the E.T.

yes you will notice a difference with an electrical fan. the mechanical fan is turning on the crank, its almost like getting your main pulley swapped out.